It would seem that many have a naïve view of the great Creator that defies belief. The perception that God has a mother is a claim that before God there was a woman who gave birth to 'him'. That takes some getting the head around. It also challenges scientific evidence that the creation we see everywhere around us has virtually no limit in age related terms. We don't know how old it is or how it came about but there are many guesses with no conclusions and many denials without evidence.
Why then would God have a mother? What kind of thinking is behind the proposal and for what purpose does it serve? The answer is not as crazy as one might expect.
The ancient world comprised thinkers who were constantly challenged about how things came to be and they devised the misinformed answers about who is in charge of the world and of all life. Slowly they built up a picture of how the sun is the master of all we survey. It was, in effect, the great mother. This can be determined through linguistics where the symbols and sounds of yesteryear are retained in language, religious beliefs and in the archaeological records.
'Ma' is mother in all languages. 'R' or 'ra' means 'power' and [a] and [i], as with other vowels were interchangeable. In many tongues and dialects the vowels continue to interchange depending on who is speaking. Putting the two symbols or 'syllables' together as 'ma-ra' or 'ma-ri' it is interpreted as 'mother's power'. It is found as such in ancient cultures where the name 'Mari' gave rise to 'Maori', 'Maya' and so on. 'Mary-gold' is the name of the flower that is named for the sun and 'mary' was the name of the Mother God - the Sun.
In all sun worshipping religions this was the high power and it was respected as such so no one could or would undermine. As the Mother God it could never be done away with.
So it was in the Roman Empire when Constantine saw his chance to govern without other rulers being involved. He obviously determined to use the religious powers of the day to enhance his cause. Having achieved sole rule through murder, stealth, deception and violence he created a religion in which he placed an image of the so-called 'son of God' and forced everyone to worship it. His edicts survive declaring the same.
That image was declared a god in the form of Jesus Christ and it was a natural event to make it the son of the Mother God so that it would be received without challenge. So Mother God became Mother of God when he declared that his Christ was part of the Trinity God borrowed from the Vedic Trinity of India. Revelation 13:13-18 tells of how he did this and of the power he had to make everyone worship the image while Mary became the chief God of his religion. It is to her, the sun, that Catholics continue to pray as part of the conspiracy to better the cause of the emperor who is identified in this prophecy as 666.